Microsoft today announced that on this Friday, January 29, it will release the first technical preview of Azure Stack - basically Microsoft Azure public cloud but tuned to run on on-premises.

Azure Stack is a "stack" of technologies that customers and/or hosting partners can run in their own datacenters. It's meant to encourage customers who can't or won't move to the public cloud to still get some of the technological and operational cloud-computing benefits with an on-premises product.

The first technical preview of Azure Stack will include a host operating system, plus a number of Windows and Linux virtual machines that can run various services. The host operating system is not some version of Windows Server; instead, it is a number of Windows Server technologies customized to run on approved hardware components selected by the customer.

Customers of Microsoft Azure should appreciate that Azure Stack offers a management portal that’s almost exactly the same as what you get in the Microsoft Azure public cloud. The services in Azure Stack can be programmed using the same application programming interfaces (APIs) as the ones available for the Azure public cloud services. And Visual Studio will integrate with Azure Stack just as it integrates with Azure.

Over time, Microsoft will add more and more Azure services in Azure Stack. For example, Microsoft thinks Azure Stack will contain Premium Storage and API Apps in preview when it hits general availability in the future.

Above: Microsoft expects to include the Azure services in green boxes in Azure Stack when the product hits general availability. Microsoft expects that the services with stars will be in preview at the time of general availability for Azure Stack.